1. Field of the Invention
The present invention relates to an image creation method, a substrate inspection method, a recording medium having a program recorded thereon for executing the image creation method or the substrate inspection method, and a substrate inspection apparatus.
2. Description of the Related Art
In a photolithography step in a manufacturing process for a semiconductor device, for example, steps of a resist coating treatment of forming a resist film on the surface of a substrate such as a wafer, exposure processing of applying and exposing a pattern on the surface of the substrate, a developing treatment of developing the substrate after exposure and so on are performed. The substrate undergone any one of the steps is subjected to a so-called macro defect inspection for whether or not a predetermined resist film is formed on the surface of the substrate, or whether or not appropriate exposure processing is performed, and further whether or not there is a flaw, an adhered foreign substance, by a substrate inspection apparatus.
The macro defect inspection is performed such that an imaging device, for example, a CCD line sensor moves relative to a mounting table mounting the substrate thereon, to capture an image of the relatively moving substrate, and performs image processing on the image to judge the presence or absence of the defect (see, for example, Japanese Laid-open Patent Publication No. 2007-240519, Japanese Laid-open Patent Publication No. 2001-91473, and Japanese Laid-open Patent Publication No. 2010-19561). In particular, the inspection can be performed by the procedure of digitally processing the image taken by the imaging device by, for example, a computer or the like, taking a difference between pixel values of corresponding picture elements in the digitally processed image data and image data of a reference image, and judging a location where the absolute value of the difference exceeds a fixed threshold value as being abnormal.